The proliferation of small intestinal epithelial cells is fundamental to intestinal development and barrier function maintenance in infants and young children. To investigate the effects and mechanisms of ω-3 polyunsaturated fatty acids (docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA)), commonly used in infant formula, on this process, this study employed the rat intestinal epithelial cell line 6 (IEC-6) as a model. After DHA and EPA treatment at different combinations of concentration (1, 10, 50, 100 μmol/L) and duration 12, 24, 36, 48 h, cell viability was assessed using the cell counting kit-8 and 5-ethynyl-2’-deoxyuridine assays, and the mRNA and protein expression of key molecules involved in the Wnt/β-catenin signaling pathways were analyzed via real-time quantitative polymerase chain reaction and Western blot. The results showed that both DHA and EPA significantly promoted the proliferation of IEC-6 cells, with optimal concentrations of 100 and 10 μmol/L, respectively, and an optimal treatment duration of 24 h. Specifically, treatment with 100 μmol/L DHA and 10 μmol/L EPA for 24 h increased cell viability by nearly 4- and 3.5-fold compared to the control group (P < 0.001), respectively. Both DHA and EPA activated the Wnt/β-catenin signaling pathway, significantly upregulating the mRNA and protein expression of cell proliferation-related genes such as cyclin D1 and β-catenin (P < 0.05, P < 0.01, or P < 0.001). These findings indicate that DHA and EPA enhance intestinal epithelial cell proliferation by activating the Wnt signaling pathway.

The in vitro simulated gastrointestinal digestion characteristics and peptide profile of partially dephosphorylated β-casein (PDP-BCN), prepared enzymatically, were determined via dynamic light scattering (DLS), confocal laser scanning microscopy (CLSM), and liquid chromatography-tandem mass spectrometry (LC-MS/MS). The results demonstrated that the flocculated structures and particle size formed by PDP-BCN in simulated infant gastric fluid were significantly smaller than those of native β-casein (β-CN), making it more easily digested into smaller particles. Moreover, during simulated infant gastrointestinal digestion, PDP-BCN degradation generated 880 peptide fragments, far exceeding the 533 peptides produced by native β-CN. This difference in peptide fragments was particularly notable at the N-terminal region of the protein. Additionally, PDP-BCN degradation yielded 8 unique bioactive peptides and 137 peptides with potential bioactivity, exceeding both the number and functional diversity of peptides derived from native β-CN. Therefore, PDP-BCN exhibited significant advantages over native β-CN in terms of digestibility. This study provides a theoretical basis for the future application of PDP-BCN as a novel protein ingredient in infant formula.

Following the aging of the population, cognitive impairment is becoming a major public health issue. Research in recent years has highlighted the potential of docosahexaenoic acid (DHA), folic acid (FA), and phosphatidylserine (PS) to improve synaptic plasticity and reduce inflammatory response. However, whether a combined intervention is more effective than using these supplements alone remains unclear. To investigate this, we conducted an experiment on D-galactose-induced aging mice and found that the combining DHA, FA, and PS (DFP) improved spatial learning memory. Moreover, the DFP treatment restored cognitive performance by regulating antioxidant levels, inhibiting microglia activation, and reducing inflammation. The treatment also increased the expression of neurotrophic factors and synaptic-related proteins in the hippocampal region of the brain. Our findings suggest that the supplementation of DPF could be more beneficial than using DHA alone. This combined intervention could improve neurotrophic factor expression and decrease neuroinflammation in the brain of mice, thus reducing neuron damage and enhancing synaptic plasticity. In summary, our results indicate that the combined supplementation of DFP may improve cognition, and may be more effective than supplement with DHA alone.